This disclosure relates to reducing pressure pulsations and noise transmission in a fluid system, and more particularly, to damping pressure pulsations and attenuating noise transmission in a fuel supply system, e.g., on an automotive vehicle.
It is believed that noise has traditionally been a problem in most fuel delivery systems. In such systems, each moving component has the potential to create or propagate noise. Examples of such fuel system components include fuel injectors, pressure regulators, fuel pumps, and check valves. Additionally, it is believed that mechanical vibration that is imparted to a fuel system can generate noise at its own signature frequency.
One type of known pressure pulsation damper includes a spring and a diaphragm. However, this type of damper suffers from a number of deficiencies. For example, it is believed that this type of damper is effective only for lower frequency pressure pulsations, i.e., in a range of 20-100 Hertz. Such lower frequency pulsations can be caused by the operation of fuel injectors. The effective damping range for a spring and diaphragm type pressure pulsation damper is believed to be achieved as a result of a relatively high degree of flexibility or pliability. However, this same flexibility or pliability causes spring and diaphragm type pressure pulsation dampers to be ineffective for damping higher frequency pulsations. Applicant has recognized that a more rigid structure is required for damping such higher frequency pulsations.
It is believed that for fuel systems there is a need to damp pressure pulsations and attenuate noise transmission in a higher frequency range, e.g., 200-500 Hertz. This higher frequency range is believed to be well above the operating range of spring and diaphragm type pressure pulsation dampers.
The present invention provides an apparatus damping pressure pulsations and attenuating noise transmission in a fluid supply system. The apparatus includes a first end in fluid communication with a fluid supply line, a second end in fluid communication with a manifold, and a body that couples in fluid communication the first and second ends. The first end is adapted to receive fluid from a pump. The second end is adapted to supply the fluid to a plurality of nozzles in individual fluid communication with the manifold. And the body includes a tube that is arranged in a helix around a central axis.
The present invention also provides a system that delivers fuel to an internal combustion engine. The system includes a tank that stores fuel at a first pressure, a fuel injector that dispenses the fuel, and an apparatus in fluid communication between the tank and the fuel injector. The fuel is supplied to the fuel injector at a second pressure. The apparatus includes a first end in fluid communication with the tank, a second end in fluid communication with the fuel injector, and a body that couples in fluid communication the first and second ends. The body includes a tube arranged in a helix around a central axis. And the apparatus damps pressure pulsations and attenuates noise transmission due to variation in the second pressure.
The present invention also provides a system for delivering fuel to an internal combustion engine. The system includes a tank that stores fuel, a fuel injector that dispenses the fuel, and an apparatus in fluid communication between the tank and the fuel injector. The apparatus reduces pressure pulsations to an approximate range of xc2x110.0 kilopascals, or attenuates noise by approximately 10 decibels, as compared to a system without an embodiment according to the present invention, over an approximate range of 160-250 hertz.
The present invention also provides a method of damping pressure pulsations and attenuating noise transmission in a fuel delivery system. The method includes supplying fuel from a tank to at least one fuel injector, the supplying includes conveying the fuel through a coil having at least one loop, and uncoiling and recoiling the coil in response to variations in fuel pressure. The uncoiling and recoiling provides infinitesimal volumetric changes in the coil.
The present invention also provides a method of damping pressure pulsations and attenuating noise transmission in a fuel delivery system. The method includes supplying fuel from a tank to at least one fuel injector, the supplying includes conveying the fuel through a tube curving around a central axis, and straightening and recurving the tube in response to variations in fuel pressure. The straightening and recurving provides infinitesimal volumetric changes in the tube.